Flash of unstyled content (FOUC)

Hi bcobin

yeah there are quite a few issues I discovered with flex box and CLS metrics too.

have you got an example site that is most affected by the issue? just curious how heavy the styles are on it.

have you tried this example?
https://medium.com/@fbnlsr/how-to-get-rid-of-the-flash-of-unstyled-conte...

I get this too, but only on Firefox in my dev environment (no caching). It seems to happen when I make a css change that causes drupal to calculate something in the background. Seems almost like a browser caching issue trying to use old files that no longer exist or something. I have never seen it in production or on Chrome.